package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;


/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Autowired
    private IUserService iUserService;

    @Resource
    private IUserService userService;

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    @Autowired
    private IFollowService followService;

    @Override
    public Result queryBlogById(Long id) {

        Blog blog = getById(id);

        if (blog == null) {
            return Result.fail("笔记不存在！");
        }

        // 查询blog有关的用户
        User user = iUserService.getById(blog.getUserId());
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());

        isBlogLiked(blog);
        return Result.ok(blog);
    }

    /**
     * 当前用户是否点赞了这个笔记
     */
    private void isBlogLiked(Blog blog) {
        // 获取登录用户
        Long userId = UserHolder.getUser().getId();

        if (userId == null) {
            return;
        }

        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();

        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());

        blog.setIsLike(score != null);

    }

    @Override
    public Result likeBlog(Long id) {
        // 获取登录用户
        Long userId = UserHolder.getUser().getId();

        String key = RedisConstants.BLOG_LIKED_KEY + id;

//        Boolean status = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());

        if (score == null) {
            // 未点赞 数据库点赞数加1
            boolean status1 = update().setSql("liked = liked + 1").eq("id", id).update();

            if (status1) { // 成功保存到redis
//                stringRedisTemplate.opsForSet().add(key, userId.toString());

                stringRedisTemplate.opsForZSet().add(key, userId.toString(), LocalDateTime.now().atZone(ZoneId.systemDefault()).toInstant().toEpochMilli());
            }
        } else {
            // 已经点赞
            // 数据库点赞数减1
            boolean status1 = update().setSql("liked = liked - 1").eq("id", id).update();
            if (status1) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }

        return Result.ok();
    }

    @Override
    public Result queryHotBlog(Integer current) {
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            Long userId = blog.getUserId();
            User user = userService.getById(userId);
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
            isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key = RedisConstants.BLOG_LIKED_KEY + id;

        // 查询 top 5的点赞用户
        Set<String> range = stringRedisTemplate.opsForZSet().range(key, 0, 4);

        if (range == null || range.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }


        // 将 Set<String> 转为  List<Long>
        List<Long> collect = range.stream().map(Long::valueOf).collect(Collectors.toList());
        String join = StrUtil.join(",", collect);
        // 根据用户id 查询用户 将User转为UserDTO 并放到一个List里
        List<UserDTO> res = userService.query().in("id", collect).last("order by field(id," + join + ")").list().stream().map(user -> {
            return BeanUtil.copyProperties(user, UserDTO.class);
        }).collect(Collectors.toList());


        return Result.ok(res);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean save = save(blog);

        if (!save) {
            return Result.fail("发表失败!!");
        }

        // 查询笔记所有粉丝
        List<Follow> followUserId = followService.query().eq("follow_user_id", user.getId()).list();

        // 推送
        for (Follow follow : followUserId) {
            Long id = follow.getId();

            String key = RedisConstants.FEED_KEY + id;

            stringRedisTemplate.opsForZSet().add(key, blog.getId().toString(), System.currentTimeMillis());
        }

        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        // 获取当前用户
        Long userId = UserHolder.getUser().getId();

        // 查询收件箱
        String key = RedisConstants.FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);

        // 非空判断
        if (typedTuples == null || typedTuples.isEmpty()) {
            return Result.ok(Collections.emptyList());
        }

        // 解析数据
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) {
            ids.add(Long.valueOf(tuple.getValue()));
            long time = tuple.getScore().longValue();

            if (minTime == time) {
                os++;
            } else {
                minTime = time;
                os = 1;
            }
        }

        // 根据id 查询blog
        String join = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id," + join + ")").list();

        for(Blog blog : blogs){
            User user = iUserService.getById(blog.getUserId());
            blog.setName(user.getNickName());
            blog.setIcon(user.getIcon());
            isBlogLiked(blog);
        }

        // 返回结果
        return Result.ok(ids);
    }
}
